It is known, for example from GB 2 234 011 to provide an internal combustion engine comprising a cylinder block, an upper crankcase, a lower crankcase, a crankshaft and a sump attached to a skirt on the cylinder block and defining a sump region, wherein the lower crankcase comprises an inner casing attached to the upper crankcase such that the upper crankcase and the inner casing support the crankshaft.
This design suffers from the disadvantages that noise is transmitted from the inner casing to the sump and transferred from the upper crankcase to the sump.